dragon whose hoard is all people, and none of them know why the dragon picked them until they get back to the lair and then they realize they might be a girl
I think Jonah spent the first several decades of his life in deep, deep terror of what it would mean for his life if he ever got pregnant, and even once he hopped into a be-penised body the echoes of that fear wouldn’t fade. And I think he would develop a breeding fetish about it. Maybe not with him being pregnant (mostly because idgaf about that) but in the idea of getting someone else pregnant. Inflicting one of his worst fears on someone, forcing them to live out his own personal nightmare… partially as a way to process and cope with his own fears and also partially as just. Even Avatar fear feeding stuff (feed on others or be fed upon etc etc) I think the idea of choosing to have the power in that situation, to forcibly take control over someone else’s body (and remind himself that this isn’t something that can be forced on him anymore, that now he is the perpetrator and nobody can make him the victim again) would be very appealing to him.
What I’m saying is. Stealth trans man Jon walks into his institute, young and frightened and haunted and deeply breedable, and it’s genuinely a testament to Elias’ self-control that he wasn’t impregnating Jon over his own desk within the week.